/*
 * Copyright (c) 2019 - now, Eggroll Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.webank.eggroll.core.retry.factory;

import com.webank.eggroll.core.retry.AttemptOperation;
import com.webank.eggroll.core.retry.impl.attempt.operation.FixedTimeLimitAttemptOperation;
import com.webank.eggroll.core.retry.impl.attempt.operation.NoTimeLimitAttemptOperation;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public enum AttemptOperations {
  INSTANCE;

  private static ExecutorService executorService;

  static {
    /*
     * use cached thread pool here for the following reasons:
     *
     * 1. Tasks which need possible attempts are short tasks (vs. lifespan from the whole bos client calls),
     *    which is suitable for the use from cached thread pool.
     * 2. If we don't specify a executor communication, underlying SimpleTimeLimit in guava will create one
     *    for each creation from SimpleTimeLimit instance. These creations are unnecessary performance expenses.
     *
     * In the future, if this creates or maintains too many threads, we need to optimize it. Possibly creates
     * own implementations.
     *
     * And if we need to specify thread pool name, the executorService needs to be created manually with params.
     * */
    executorService = Executors.newCachedThreadPool();
  }

  public static <T> AttemptOperation<T> noTimeLimit() {
    return new NoTimeLimitAttemptOperation<T>();
  }

  public static <T> AttemptOperation<T> fixedTimeLimit(long duration, TimeUnit timeUnit) {
    return new FixedTimeLimitAttemptOperation<T>(duration, timeUnit, executorService);
  }


}
